Promise join为链添加新函数调用

Question

I am trying to load and parse a file, but am having some trouble calling two functions and returning the result for the promise. I am using bluebird promises. The following code works as expected:

run = function (filePath) {
    return Promise.join(
        fs.readFileAsync(filePath, 'utf8')
            .then(parseFile.parse.bind(null, 'userKey')),
        users.getUsersAsync(usersObj)
            .then(users.modifyRec.bind(null, process.env.users))
    ).then(function (args) {
            return runProc('run', args[0], args[1]);
....

I have divided the parseFile.parse function into two methods, parseFile.parse and parseFile.getProp . parseFile.getProp should take the output from parseFile.parse and return what parseFile.parse returned before the method was split up. Here is my attempt to use both functions:

run = function (filePath) {
    return Promise.join(
        fs.readFileAsync(filePath, 'utf8')
            .then(parseFile.parse.bind(null, 'userKey'))
            .then(parseFile.getProp.bind(null,'key')),
        users.getUsersAsync(usersObj)
            .then(users.modifyRec.bind(null, process.env.users))
    ).then(function (args) {
            return runProc('run', args[0], args[1]);
....

but it isn't working. What am I doing wrong here?

UPDATE

var ymlParser = require('yamljs');
var ymlObj;

parse = function ( data) {
    "use strict";
    if (!ymlObj) {
        ymlObj = ymlParser.parse(data);
    }
    return ymlObj;
};

getProcWeb = function () {
    return ymlObj.prop.web;
};

module.exports = {
    parse: parse,
    getProp: getProp
};

Answer 1

Promise.join won't return an array, in your case - args[]. Promise.all will return an array.

So in your case, you should either change your Promise.join syntax to

    Promise.join(
         fs.readFileAsync(filePath, 'utf8')
           .then(parseFile.parse.bind(null, 'userKey'))
           .then(parseFile.getProp.bind(null,'key')),
        users.getUsersAsync(usersObj)
           .then(users.modifyRec.bind(null, process.env.users))
       ,function(argsOne,argsTwo){
           return runProc('run', argsOne, argsTwo);
   }));

Or use Promise.all

   Promise.all([promise1, promise2]).then(function(args){
       return runProc('run', args[0], args[1]); 
   });